After talking to Cissy from Sofirn (@ AliExpress) I was informed that the discussion will roll until the next weekend (7th January). After that, their engineers will pick the suggestions from the thread and will work on Sofirn’s new model.

About the testing, I asked Cissy if they will make a “pre-production” for tests or just a final version. I will be waiting her answer and will post it here then!

The discussion may still keep going on after 7th January, but the post #2 will stop being updated after that day! Post #3 may be updated if there is any information from the manufacturer regarding the flashlight’s building!
I hope you understand this decision
Thanks for participating on this

The aim of this contact was to ask the “community” some comments/suggestions to build this new model, starting from some specs that I’ll list below, given by the manufacturer.

In a message today Cissy also mentioned: “this parameter is not the final design, we may do some available change according to customers demand”.
From here we can see Sofirn’s openness to suggestions from the final users, a feature I’ve been liking in this brand’s work so far

Cissy added that some units will be sent to some members for testing purposes! I’m not sure how it will happen but, please, manifest your interest if you are interested to receive an exemplar to test. The manufacturer will then decide to whom they will send.

- Below you will find the information given by Cissy about the new model.
- On Post #2 I will put some general topics to add the information given by BLF members.
If you have any suggestions (for topics or contents) or questions, please post them.
- Post #3 will be reserved for further answers by the manufacturer, if needed, and the interest list for reviewers/testers.

I will send Cissy this thread’s link so they can see it and follow it.
Also, I will check this thread regularly on the next days and update Post #2 the best I can with your info.

PLEASE, be CONCISE and OBJECTIVE in your comments and questions! That’s the only thing I ask to help me organising the information!

__________________________

NOTE 1 >>>> I am not – in any way – related/affiliated to Sofirn or their business! Except for being a costumer, of course! Also, so far, I don’t have any other information about this model, so if you have questions, please add them as well!

NOTE 2 >>>> As far as I perceived, Sofirn reserves themselves the right to implement or not the given suggestions. So, if the final models do not incorporate what will be said, I can’t be blamed on that.

As far as I perceived this flashlight will have 1 Ramping group and 2 Mode groups.

How to turn OFF:
1) in Ramping group, fast click to turn OFF
2) in Mode Groups (2), press the switch for 0.5 seconds to turn OFF

- From OFF:
a) fast click to get the lowest brightness level (not the moonlight, which modes brighter than Moonlight.)
b) hold 0.5 second to get Moonlight
c) hold 1 second to get a memorized mode
d) fast click & hold 1 second to get a light, which used as night indicator outdoor; one click to turn off

- Group 1 (Ramping): at 52ºC, the light steps down firstly (above 1200lm, it adjust to 600lm; less than 600lm, no change); 60℃, the light steps down secondly.

- Group 2 (5 Modes): at 52ºC, the light above 600lm, steps down to Med; the light below 600lm, steps to Low; at 60℃, the light steps down secondly.

- Group 3 (6 Modes): at 52ºC, the light above 300lm, steps down to Med; the light below 300lm, steps to Low; at 60ºC, the light steps down secondly.

The thermal stepdown function stops if we manually adjust the light to higher mode when it stepped down. Then the light works for 3 minutes to step down to the original mode; turn OFF, and activate the light again, the thermal stepdown function works.

GENERAL ASPECT / DESIGN
- Change the style extruded tube with simple tube with big bore inside. With parallel connection it will allow to use 3×21700 or 4×18650 with same tube. (kiriba-ru)
- “combined/synchronized machining of head and body threads to enable precision and alignment of the 2 parts when screwing them together till the end” (kiriba-ru)
- A tube that’d hold 3× 26650 cells, and a head that can hold 3× 26mm TIRs. (Lightbringer)
- single 26650 and a Ledil cute SS triple optic in a tube light like the SP33 (ZozzV6)
- a different battery tube than the default SRK battery tube, just to distinguish themselves from the many many cheap crappy clones with the same battery tube design (Jerommel)
- Make the tub a big block knurling or big diamond shape but not the SRK (ZozzV6)
- slightly smaller (3×18650) size, it might be just that much more easily carried. (PBWilson)
- cartridge for 4 batteries (Serp)
- 3×21700 batteries (kiriba-ru)
- 4×18650 (suratyu)
- 4×18650 (Andybibbville)
- battery carrier is better than fixed tube because it is easier to mod 2S2P and replace the leds with 6V ones (ZozzV6)
- Batteries should be 18650 or 26650. 4× 18650 is a bit too fat to be easily carried. How about 2 × 26650 in parallel? An oval cylinder battery tube might be easier to hold. (Andrew_Debbie)
- Deal with the heat, have a nice and current UI (ramping?), make sure the switch works well and come in at a nice price and you’ll bound to be a winner. (PBWilson)
- The battery holder should be careful with the interior design, not to damage the battery side wall during insertion. Each slot should be well separated, and the battery will not lean over the other slot. (WestBam)
- External dimensions: Do not have a very large diameter because many people can not handle it comfortably. (WestBam)
- Head: good if the size is the same as the size of the body and not bigger. This makes it easier to carry while it is in use, taking up less space.(WestBam)
-

____________________EMITTERS AND MCPCB
- high cri nichia 219C’s (RobertB)
- 3 XHP50.2 or XHP70.2 on deeper reflectors (AlexGT)
- 3 XHP70.2 (NikolaS)
- 3 XHP35-HI (gchart)
- XP-L HI emitters (Delta_V)
- 3 XHP50 CRI90 (Lexel)
- MCPCB designed dual footprint with XHP50 thermal pad non conductive (1206 Resistor pad bridge for example) (Lexel)
- 3*XPL and 3*XPL-HI (Jackie)
- 6 Luxeon V (4000K) (WTF)
- 6 XP-L or 6 SST-40 (giorgoskok)
- XP-L HI and Nichia 219C; Copper DTP MCPCB (XXX-Man)
- Two emitters options isn’t a bad idea. XP-G2 or G3 for the budget option, and XP-L HI for the lumen hungry, maybe a third Nichia option (leaftye)
- some 4Cs/4300Ks in there, or some 4500K Nichias. Make a WW option, too. 3000K ; 4500K is low-stress on the eyes (Lightbringer)
- 7 emitters would fill the head nicely, like a flower pattern (6 in a circle with 1 in the middle) (Jerommel)
- High CRI Nichia (Jerommel)
- 3x or 4x Luxeon V and drive them hard and get close to 6000 or 8000 Lumen (Jerommel)
- warmer to neutral tint with a nice balance of flood and throw (PBWilson)
- 3 XHP50.2; 3-5mm base with a direct heatsink (Serp)
- triple design; XHP 50.2; 3 XHP 50.2 in 6-volt configuration at half of their max forward current? (Jaded)
- 3 xhp70.2 (suratyu)
- 3 xhp70.2 (Andybibbville)
- 7 (emitters) is best: uses almost all of the front surface, without dramatic cutting of the cups; no dramatic petals in the spill and decent throw (Jerommel)
- 219C, but the beam pattern and tint shift problems would be better with TIR optics. (Jerommel)
- 7x Luxeon V it is quite possible to reach 14000 Lumen (before optics) on freshly charged (high drain!) cells. (Jerommel)
- 8x Luxeon V it’s easy to get 8000 lumen, regulated for the most part of the battery charge. Turbo could be 16000 lumen. (Jerommel)
- 7 as most efficient reflector or TIR lens usage. Then don’t need to push every led so hard and they can work more efficient. (ZozzV6)
- 90+ CRI 4500K option (Andrew_Debbie)
- 7 units, all regular circular reflectors, center plus six surrounding. No reflector bastardization with great use of available area (Barkuti)
- 7 emitters (JudgeDredd)
- benefits of 8 LEDs. You can split it into 2×4 or 4×2, which is better when you have a sense resistor before the FET. (Jerommel)
- number of emitters, we have to remember it is also a matter of price, and the number 6 might have been reached as a production cost limit. If not, well, than I’m all up for a K7 instead of a K6 (Persechini)
- LED: Combine the same loads of LEDs in the SMO and OP reflectors. Eg XPL-HD is the OP reflector and XPL-HI is the SMO reflector. You get beautiful throw and a large flood in one flashlight. (WestBam)
-

____________________DRIVER
- 2S/2P Boost for 3 XHP35/50 12V (Lexel)
- quality boost driver or FET driver (giorgoskok)
- driver that can supply it plenty of current and still have a great UI; just go for one of the BLF drivers. Forget all the development hassles and adopt something that works and is loved. (leaftye)
- current regulated driver (With 1S4P battery config you can supply 7× 3535 LEDs with the necessary current) (Jerommel)
- buck driver for xhp50.2@12v (Serp)
- current limited FET driver (Jerommel)
- boost driver with 7S emitter output voltage window (at least up to 28V) and 3S/4S input voltage, with 4S_18650 and 3S_21700 battery carriers. Driver can be designed to detect battery carrier type and adjust battery input voltage cut-off accordingly: down to ≈11V for 4S and down to ≈8V for 3S, for example. (Barkuti)
- implement a ludicrous beam mode by pumping ≈6A to all XP-L emitters in series. For high bin XP-Ls this would mean 14Kilolumens before stepdown (Barkuti)
-

____________________USER INTERFACE
- optimize the ramping UI (comparing to the one of SP32A) making it faster from bottom to top, and more even between the lower and higher levels, without “stopping” during some luminous levels (MascaratumB)
- The non-ramping mode group should have “click + press & hold” to change modes and “fast click” to turn off (…) less likely to accidentally register a double click; I also find a short click to turn off to be more intuitive than a long press. It would also be more consistent with the ramping mode – in either group, press&hold would change brightness while a click would turn the light off. (Delta_V)
- from OFF short click last memorized mode or first mode of mode order if disabled (Lexel)
- long click from OFF Moonlight (Lexel)
- 4 clicks from ON as well lock out (Lexel)
- Option to Moonlight with down to 0.1 lumens in ramping (Lexel)
- option to enable/disable memory (Lexel)
- in modes an option to enable/disable moonlight and change mode order (Lexel)
- 3 short presses for strobe advance with long click to beacon and battery blink out, normal click to last mode (Lexel)
- enabling or disabling Memory as an option in the ramping group [If memory enabled the fast click from off would be the memorized mode. If Memory disabled the fast click from off would go to the Low (non Moonlight mode)] (vwpieces)
- use Andúril (made by ToyKeeper) (Persechini)
- more even mode-spacing in discrete-step modegroups (Lightbringer)
- fast click to turn OFF (Xoden)
- Ramping (PBWilson)
- NO STROBES (Lightbringer)
- Driver and Modes: Be Easy! Do not complicate it like BLF Q8. I got a lot of feedback on how good the description is, but the menu is still complicated. Anyone who wants to buy it is not programmed. or not want to change the final user firmware! The ramping I think is quite useful. Let the two endpoints be well interpreted and that’s all. The moonlight mode should be really low for a terrific long running time. Heat protection works reliably and independently. (WestBam)
-

____________________LOW VOLTAGE PROTECTION
-
-

____________________THERMAL STEPDOWN
- if this is not calibrated and based on MCUs spread this will be not good, some will be too high others too low, I calibrated a hundred Narsil drivers and the spread is +10°C/-15°C sometimes even 20°C (Lexel)
- get this with a external NTC on the MCPCB and raise temp to 80°C (Lexel)
- the thermal step-down should use a slow dimming down instead hard step-down’s (Lexel)
- Set high level around 2400 lumens and give it enough thermal capacity so the light can run continuously without stepping down (WTF)
-

____________________OTHER ASPECTS
- add tripod mount (WTF)
- springs bypassed; brass screws holding the springs pcb (giorgoskok)
- The spring PCB at the negative side should be made with very very big traces for high current, to avoid melting if a battery is placed in reverse position (ZozzV6)
- Battery level indicator is definitely useful, the light under the button is probably the most good. I like to see a metal button on the side of the body and a lighted ring. (WestBam)
- Exterior: Have a tripod mount, when you have a high weight (over 500g) on the head and body at the end of a decent size and wall thickness hole to use a shoulder strap to it. (WestBam)
- threaded tripod hole would be good (leaftye)
-

____________________QUESTIONS to the manufacturer
- How low is the Moonlight Mode? If it is not on the regular modes – that start on 100lm or 200lm – how low is it? (MascaratumB)
- I wonder what pricepoint they’re going after. If it’s going to be less expensive than a Q8 or similar 4×18650 lights that have been released recently, what options are they willing to lose? Simpler UI? Less machining? Less involved emitter setup? No spring bypass? (PBWilson)
- Since Sofirn came on the market as a budget priced light, are they going to follow that model or is this going to be in the $80-$100+ price range? If it’s going to be less expensive, drop any ideas of changing ports and box candy. A few extra o-rings should do it. (PBWilson)
-Would it be possible to make a light with Jerommel’s 7 LED configuration and have the center LED be a thrower, and the six surrounding LED’s be floods? Perhaps with independent control of them. Or is this a bad idea given the way lights get used in the real world? (Lazy-R-us)
-

____________________EDITCOMMENTS:
- A place for a light like this in the market, due to similarity with the BLF Q8, with similar UI.
- make the host available (MikeC)
- make a different kind of light like a triple led tube form 26650 light or something else because this is very close to Q8; This could be a good light because the UI is pretty good and I hope there will be a lot mass in the head but Q8 mostly filled the requirements for this type of light. (ZozzV6)
- 15k+ lumens would make this light stand out, and Nichia emitters are another way to make it special. (leaftye)
- With many 3535 LEDs (with appr. 2mm² Light Emitting Surface, like 219C and XP-G3) you can use smaller optics for the same throw, which also means they can be shorter and with 7 LEDs With a (regulated) FET driver in stead of a buck or boost driver, the driver board can be flat. So in all, they could make it a short, compact light (Jerommel)
- something a little different than the Q8, perhaps a little smaller and simplified for an even more affordable cost (PBWilson)
- make the K6 host available for sale (Jaded)
- Do not do another skyrayking. (Serp)
- Q8-inspired, C8F hybrid has a good potential (Jaded)
- dealing with heat and having an up to date UI are the most important features (PBWilson)
- Making it moddable (no glue!) would satisfy those who want to tweak it and still keep it usable and safe for those who don’t. (PBWilson)
- The difficulty with XHP LEDs is the voltage. You’ll need expensive buck or boost drivers. The .2 versions of these LEDs have some serious tint shift issues in aluminium reflectors. You need more complicated battery contact boards too. I don’t know what Sofirn wants to make, but it looks like a simple 1S4P battery set up, they’re thinking of 6 LEDs. So why not 7? Either way, you don’t have to have a buck or boost driver to drive multiple LEDs in parallel. (Jerommel)
- If they want to go for BIG output, they should use the new Luxeon V LEDs, have them run on 4.5 Amperes each, which means 31.5 Amperes in total, divided by 4 batteries is 7.875 (let’s say 8) Amperes per 18650. Luxeon V is quite good in regular aluminum reflectors. And with their low Vf (forward voltage) you can run them current regulated for a good part of the battery charge, unlike with FET DD drivers (which is why i don’t like DD drivers, they’re actually not even drivers…) (Jerommel)
- FET DD driver lights usually have high Vf LEDs like XP-L and XP-G2, because they don’t draw too much current on a freshly charged cell. Batteries and low Vf LEDs can get into trouble with DD drivers, unless you use lossy springs and thin wires, which is just a lame solution. I don’t know if Sofirn is into driver design, but it’s only a few more parts from and FET DD driver to a FET regulated driver. Probably they want a LED board with all LEDs in parallel config, only need two fat wires (16 or 18 AWG should do). (Jerommel)
- why not what looks like the acebeam x80 configuration? (about the number and disposition of the emitters) (Gerrit)
- The K6 has a better balance between complexity and flexibility. I especially like the side switch battery indicator. The lack of strobe is another plus. (Andrew_Debbie)
- Is a single emitter possible at this power level? If it is I would prefer a single emitter in a flood pattern.If not, would 5, 7 or 9 emitters be a better use of space and better beam pattern? An odd number allows a centre emitter. (Andrew_Debbie)
- ability to (factory) switch emitters with minimum to no driver reconfiguration (Barkuti)
- change the name to K7! (JudgeDredd)
- The Voltage drop over the sense resistor will be significant with 7 or 8 LEDs in parallel on 1 single FET. But maybe that’s just a matter of making the sense resistor 7 or 8 times smaller, but when you satrt out with 0.01 Ohm, you’ll end up with something like 0.00115 Ohm, which is possibly lower than the PCB traces and / or LED wires.. (Jerommel)
- I wonder what Sofirn’s goal is for this particular light. Is it to compete with the BLF Q8 and ride the wave of its popularity? Is it going up against the Astrolux MF01 and learn from the mistakes it had? Is it an alternative to another 4×18650 light at a less expensive price point? I’m not in a hurry for an answer and maybe there’s no answer as of yet, but with all of the feedback in the Q8, MF01 and Haikelight threads, hopefully they can learn from the mistakes and produce another worthy light for us to buy. I’m hopefully optimistic based on the other Sofirn light I have. (PBWilson)
- We’ve seen a picture of the SRK, but here’s some things if you’ll be doing machining. One thing to note is that saving weight is not a good thing with this type of light. If material is machined away, it must serve a purpose. Grooving fins for heat sinking is good. Machining the LED shelf thinner is bad, very bad. I’ll just say it, leave lots of material under the LED. (leaftye)
-

____________________EDIT 2REVERSE POLARITY PROTECTION
- For polarity protection it needs plastic rings on the driver that blocks contact with negative side of battery if one reversed. (ZozzV6)
-

Why not 3 XHP-50.2 or XHP-70.2 on deeper reflectors to have a bit of throw and flood at the same time…???

I’ve got the same request from Sofirn official store, and my answer was that I am not sure that there is a place on the market for same type of light like Q8, with similar or same UI like Narsil.
Personally I like the idea of having more lumens but 6 led reflector usually have much floodier beam then with 4 led, so my vote goes to 3 XHP70.2 something like Utorch UT03 prototype ..

Also If K6 went to production,I would love to be on the list for testing.

I have one suggestion for the UI. The non-ramping mode group should have “press&hold” to change modes and “fast click” to turn off. I find this preferable to the other way around, as you are less likely to accidentally register a double click; I also find a short click to turn off to be more intuitive than a long press. It would also be more consistent with the ramping mode – in either group, press&hold would change brightness while a click would turn the light off. With the current setup, the interface changes depending on which group you are in, which is less intuitive.

I have one suggestion for the UI. The non-ramping mode group should have “press&hold” to change modes and “fast click” to turn off. I find this preferable to the other way around, as you are less likely to accidentally register a double click; I also find a short click to turn off to be more intuitive than a long press. It would also be more consistent with the ramping mode – in either group, press&hold would change brightness while a click would turn the light off. With the current setup, the interface changes depending on which group you are in, which is less intuitive.

Delta_V, just one question: when you mean “press&hold” you mean it like the Emisar D4? Or did you mean “click + press & hold”? Meaning one click for ON, then press & hold to change modes, like the Olight lights?
Sorry, I was just manipulating some of my lights and got that doubt!

Hmm, that’s a bit tough. Given that we, the BLF community, recently created the Q8 to meet our desires… creating a similar light and asking for our input might take us dangerously close back to the Q8.

I like three idea of having fewer emitters (say 3) and make them XHP50.2’s. Or better yet, 3x XHP35 HI! That way we have lumens and some throw. I mean, what does a 10,000 lumen pure-flood do for you? Blind you up close it seems to me. Don’t get me wrong, give me those lumens! Just allow me to cast them a bit farther.

And I do really like how Sofirn is accepting of feedback. Very nice. And I’m always up for testing a light

Hmm, that’s a bit tough. Given that we, the BLF community, recently created the Q8 to meet our desires… creating a similar light and asking for our input might take us dangerously close back to the Q8.

I like three idea of having fewer emitters (say 3) and make them XHP50.2’s. Or better yet, 3x XHP35 HI! That way we have lumens and some throw. I mean, what does a 10,000 lumen pure-flood do for you? Blind you up close it seems to me. Don’t get me wrong, give me those lumens! Just allow me to cast them a bit farther.

And I do really like how Sofirn is accepting of feedback. Very nice. And I’m always up for testing a light

Hum, I got the point, completely! I don’t have the Q8, and I only one “big light” (Amutorch AM30), but I see all the points about that possible comparison! I guess it will be hard to beat the Q8

EMITTERS AND MCPCB
- I would choose 3 XHP50 over 6 XPLs, because the reflectors with 6 have a relative small reflective area due to the neighbor cutouts
- Option to get 3 CRI90 XHP50
- MCPCB designed dual footprint with XHP50 thermal pad non conductive (1206 Resistor pad bridge for example)

DRIVER
- 2S/2P Boost for 3 XHP35/50 12V

USER INTERFACE
- from Off short click last memorized mode or first mode of mode order if disabled
- long click from Off Moonlight, remove c) hold 1 second to get a memorized mode
- 4 clicks from on as well lock out
- Option to Moonlight with down to 0.1 lumens in ramping
- option to enable disable memory
- in modes an option to enable/disable moonlight and change mode order
- 3 short presses for strobe advance with long click to beacon and battery blink out, normal click to last mode

THERMAL STEPDOWN
- if this is not calibrated and based on MCUs spread this will be not good, some will be too high others too low,
I calibrated a hundred Narsil drivers and the spread is +10°C/-15°C sometimes even 20°C
- get this with a external NTC on the MCPCB and raise temp to 80°C
- the thermal step-down should use a slow dimming down instead hard step-down’s

OTHER ASPECTS
-
-

Put me down for testing and review
I will even prefer a early pre production sample

Is there any pre-requisites for being in the reviewer interest list? My experience with Sofirn lights is based on older models (but I have 2 newer AA/14500 lights in the mail) and would like to contribute do making a better product, bering in mind that the recent Q8 is kind of it’s kind and a new light would benefit from not aiming at the exact same spot

Is there any pre-requisites for being in the reviewer interest list? My experience with Sofirn lights is based on older models (but I have 2 newer AA/14500 lights in the mail) and would like to contribute do making a better product, bering in mind that the recent Q8 is kind of it’s kind and a new light would benefit from not aiming at the exact same spot

Hum, pre-requisites, not that I know!
As I mentioned, concerning this light, I will list the names of the interested people for test / review, and then the manufacturer will decide on who to choose and send them! I don’t know the exact criteria – if it exists – , but it may be based on the contribution for this light’s discussion!

WTF wrote:

How about six 4000k Luxeon V emitters with a MT03 type floody beam?
Set high level around 2400 lumens and give it enough thermal capacity so the light can run continuously without stepping down.
A tripod mount would be nice as well.

I wish for enabling or disabling Memory as an option.
If memory enabled the fast click from off would be the memorized mode.
If Memory disabled the fast click from off would go to the Low (non Moonlight mode)
The above would be within the ramping group.

Or it could be a good time. There was talk about a Q8 like light with more emitters and also a triple I think. That would be a ways away. If Sofirn can keep it budget like and have consistent quality if could be a hit or a filler befor the next BLF Q8 iteration.

Also – Im not sure that this is suitable thread – but anyway:
There is one thing that are out of my machinary abilities, but defenetly can be made with tools that flashlight manufactures use.
If flashlight shape is not round or/and have some objects (side switch) that are usully imply one position when using (ie you will always hold it this way that you can manage switch with thumb), threads MUST be synchronised so the other screwing part (bettery tube) flatness was inline with this position. Maybe Im perfectionist but I dont like Q8 with tube flatness rotated by some degree relatively to the head.

Change this f#cking SRK style extruded tube with simple tube with big bore inside. With parallel connection it will allow to use 3×21700 or 4×18650 with same tube.

vwpieces wrote:

I wish for enabling or disabling Memory as an option.
If memory enabled the fast click from off would be the memorized mode.
If Memory disabled the fast click from off would go to the Low (non Moonlight mode)
The above would be within the ramping group.
But it is bad timing to introduce this format of light after the Q8.

Mike C wrote:

Not a suggestion on how to improve this light, but a plea to Sofirm to make the host available.

Suggestions above added

xCentrino wrote:

vwpieces wrote:

But it is bad timing to introduce this format of light after the Q8.

Or it could be a good time. There was talk about a Q8 like light with more emitters and also a triple I think. That would be a ways away. If Sofirn can keep it budget like and have consistent quality if could be a hit or a filler befor the next BLF Q8 iteration.

Not added, but it’s nice you posted I think you got a (very good) point on this!!

kiriba-ru wrote:

Also – Im not sure that this is suitable thread – but anyway:
There is one thing that are out of my machinary abilities, but defenetly can be made with tools that flashlight manufactures use.
If flashlight shape is not round or/and have some objects (side switch) that are usully imply one position when using (ie you will always hold it this way that you can manage switch with thumb), threads MUST be synchronised so the other screwing part (bettery tube) flatness was inline with this position. Maybe Im perfectionist but I dont like Q8 with tube flatness rotated by some degree relatively to the head.

kiriba-ru, if I understand correctly, you ask for a good “ergonomy” while grabbing/holding the light, making it easier to hold in the hands and find the switch button when/if rotating the line, right?
Like: the button aligned with a – example – flat surface on the top to have a nice grip, and also the emitters aligned well!
Is this it?

No.
Imagine that both parts (tube anc head) are square outside (or hex). If parts are first lathed, and then milled on another machine, this flat surfaces wont fit each other. I.e. you will be able to find position when they are synchronized but when you screw them all the way they wont fit. You can avoid this bug if you have combined lathe/mill machine with stepper motor or precision position sensor on main lathe axis.